But from the "doesn't that stink" file, the reviews say you're not going to make more than a few dollars from these apps.

The website DoesItReallyWork.org
investigated these programs, and says you might make a few dollars a week.
But it says using these apps is like going to Chuck E. Cheese, and finding that all your tickets will buy only some little token, not any of the big prizes you really want.

Bottom line: These sites are legitimate, but I wouldn't quit my day job.